The present invention relates generally to an apparatus and method for the percutaneous placement of gastro-intestinal devices. More specifically, the present invention relates to an apparatus and method for percutaneously placing one type of gastro-intestinal device, gastrostomy tubes having internal bolsters, by using a hollow sleeve to hold the bolster in a position such that it has a reduced lateral extent during placement, and a rip cord to release the sleeve from around the bolster.
Medical practitioners currently use Percutaneous Endoscopic Gastrostomy (PEG) and Percutaneous Endoscopic Jejunostomy (PEJ) techniques to place catheters or tubes within the gastro-intestinal tract. Three main PEG techniques are used to place gastrointestinal tubes: Sacks-Vine, Ponsky, and Russell. These techniques are well-known in the art.
Gastrostomy tubes, which are a type of gastro-intestinal tubes, often have an anchoring device, or internal bolster, on their distal ends. These bolsters are formed with a lateral extent which is wider than the penetration diameter to prevent premature removal of the tube from the penetration. The bolsters often have a dome, mushroom, or Malecot structure.
Due to the lateral extent with which the internal bolsters are formed, percutaneous placement of tubes having such bolsters through a penetration is difficult, and current techniques do not adequately provide for placement of such tubes. When placing a gastrostomy tube with internal bolster at its distal using either Sacks-Vine or Ponsky technique, for example, the tube and bolster are dragged through the esophagus and into the stomach. When performing percutaneous placement according to the Russell technique, practitioners typically use catheters with a balloon on the distal end which can be inflated once the tube is placed within the stomach, instead of using a tube having a bolster with lateral extent as described above.
Typically, the initial penetration is maintained such that a stoma, or fistulous tract, is allowed to form, which connects the stomach wall to the external abdominal wall. In the prior art, the initially-placed gastrostomy tubes are replaced using the same techniques used as to place the initial tube; i.e. according to either the Sacks-Vine, Ponsky, or Russell technique. Alternatively, they are placed by insertion through the stoma. Various devices have been used for inserting a gastro-intestinal tube having an internal bolster through a stoma. Use of these devices typically involves obturating or realigning the internal bolster, or axially elongating the internal bolster prior to insertion. See e.g., U.S. Pat. Nos. 5,248,302, 5,007,900, and 5,454,790.
Several deficiencies exist in the prior art techniques. For example, Russell technique is a complicated placement method which is not conducive to placing gastrostomy tubes having internal bolsters. In addition, those techniques which use obturation for placing tubes by insertion through a stoma often require specialized bolsters capable of engaging an obturator rod, and access tubes equipped with such specialized bolsters are typically expensive. See e.g, U.S. Pat. No. 5,248,302. Furthermore, prior art techniques which involve axial elongation and radial compression of the access tube require a grade of access tube which can sustain such axial tension and radial compression. See e.g. U.S. Pat. No. 5,454,790. Those techniques may also require a sheath capable of compressing the tube to a diameter smaller than the diameter when under axial tension or radial compression. Further still, techniques used with access tubes having T-bar bolsters in which the T-bar bolster is aligned with the tube shaft, such as that described in U.S. Pat. No. 5,007,900, often do not sufficiently reduce the lateral extent of the tube""s distal end to a size that can be easily inserted into the stoma.
The present invention is directed to an apparatus and method which facilitate percutaneous placement of a gastro-intestinal device, such as a gastrostomy tube, either through an existing penetration or by insertion where no prior penetration exists. The apparatus comprises a gastrostomy tube having a deformable internal bolster, a hollow sleeve, and a rip-cord. The hollow sleeve is a substantially tubular structure with a lubricious outer surface. The sleeve fits around the internal bolster and holds the bolster in a position such that the lateral extent of the bolster is reduced. The sleeve can be made of material that allows the sleeve to be changed to a substantially tubular form having a reduced diameter. For example, the sleeve can shrink or contract to a reduced diameter. Alternatively, the hollow sleeve can be made such that a bolster can be compressed and slid or otherwise placed within the hollow sleeve. The rip-cord is a filament, such as wire, string or fibrous thread, capable of tearing through the hollow sleeve, thereby releasing the bolster and allowing the bolster to regain its original lateral extent.
One embodiment of the present invention enables the percutaneous placement of a gastrostomy tube through an existing penetration by pushing an assembled device through the penetration, with this embodiment comprising a gastrostomy tube, a rip-cord, and a hollow sleeve. In this embodiment, the bolster is first manipulated such that its lateral extent is reduced. This manipulation can be performed by re-positioning, folding, compressing, or stretching the bolster, or a combination thereof. The lateral extent of the bolster can be reduced to a size approximately equal to or less than the tube diameter, thereby facilitating placement through the existing penetration. The hollow sleeve is placed so as to surround the rip-cord and the manipulated internal bolster, and may additionally extend to cover a portion of the tube shaft. The sleeve is preferably made of a heat-shrinkable fluoropolymer tubing, such as tetrafluorethylene (TFE) tubing, which, when heated, shrinks to fit snugly around the bolster, holding it in its manipulated position of reduced lateral extent. The rip-cord preferably runs between the gastrostomy tube shaft and the hollow sleeve, wraps over the top of the sleeve, extending proximally along the tube shaft.
The assembled apparatus can then be inserted into the existing penetration by holding the tube shaft and pushing the assembly through the penetration. In addition, the hollow sleeve can be placed such that it extends to cover a portion of the tube shaft, thereby providing additional support to the shaft and decreasing shaft buckling during insertion.
Another embodiment of an apparatus according the present invention includes an extension rod and an internal bolster with one or more pockets capable of receiving the tip of the extension rod. The rod, which is used to push the tube through the existing penetration, can be inserted through the central lumen of the gastrostomy tube to reach the bolster pocket. Alternatively, the rod can be run inside of the hollow sleeve into the pocket, or along the outside of the sleeve and into the bolster pocket.
The shaft of the gastrostomy tube may have a slit through which the extension rod can pass. The rod can be inserted into the central lumen of the tube, run so as to exit the lumen through the slit and rest within the pocket of the bolster. The slit closes upon removal of the rod, such that no materials (e.g. food or medication) can exit the tube through the slit during use of the tube.
Yet another embodiment of the apparatus of the present invention enables percutaneous placement where no penetration exists. This embodiment includes a trocar which can be used to pierce the body tissue and form a penetration. The trocar has a tapered distal end and, in addition, may have a wedge or ridge, located on the trocar shaft proximal to the tip, which tapers proximally.
The apparatus of this embodiment is assembled such that the sleeve surrounds the tube, bolster, and trocar. The tapered distal tip, however, extends distal to the distal end of the sleeve. The trocar can be inserted through the central lumen of the tube or, alternatively, the trocar can be run along the outside of the tube, inside of the sleeve. The trocar wedge engages the internal bolster or another portion of the assembly, preventing the hollow sleeve, internal bolster, and gastrostomy tube from being pushed proximally, with respect to the trocar, during insertion. The wedge essentially holds the assembly together as a unit during insertion.
Still another embodiment of the apparatus of the present invention includes a cannula which can be used to percutaneously place the gastrostomy tube over a guidewire. In addition, the internal bolster may have a bore through its entire width, such that a cannula or trocar can run therethrough.
The apparatus of the present invention overcomes the deficiencies of prior art devices in that it eliminates the need to insert the initial placement tube according to traditional PEG methods such as Sacks-Vine, Ponsky, or Russell.
In addition, the present invention can be used with a wide range of internal bolsters. Prior art replacement PEG devices utilize specialized bolsters adapted for a particular placement technique. The present invention operates with all internal bolsters which can be folded, compressed, stretched or otherwise reduced in effective diameter. Most of the bolsters currently used are made of biocompatible polymers such as silicone elastomer, silicone copolymer, or polyurethane, and can be folded to a reduced diameter. Thus bolsters with mushroom, dome, malecot, or other configurations can be used.
Using the percutaneous replacement method of the present invention, the gastro-intestinal tube, hollow sleeve, and rip-cord are assembled such that the hollow sleeve is placed over the internal bolster, holding it in a reduced diameter form; the rip-cord extends distally along the longitudinal axis of the tube, positioned between the hollow sleeve and the gastro-intestinal tube, wraps over the distal end of the sleeve, and then extends proximally along the longitudinal axis of the tube, on the outside of the sleeve. Next, the distal end of the tube is pushed through the stoma until the tube is fully inserted. The rip-cord is then pulled, tearing the hollow sleeve from the distal towards the proximal end, and thereby releasing the bolster. The sleeve and rip-cord are then pulled from the stoma, leaving the gastro-intestinal tube in place.
To facilitate placement, the gastro-intestinal tube may have an insertion handle on its proximal end.
To facilitate sleeve removal, the hollow sleeve may be longitudinally scored to aid removal. Further, two longitudinal slits may be made 1800 apart at the proximal sleeve end. These slits form tabs which may be used to pull the sleeve from the stoma. Still further, a tab may be attached to the end of the rip-cord to facilitate pulling the cord.
In addition, the sleeve can be made such that the rip-cord is integrally formed within the sleeve. This can be done using molding techniques known in the art. The rip-cord would be run along the inner length of the sleeve such that the rip-cord would tear through the sleeve when pulled.
An alternate replacement method of the present invention applies to the embodiment, described above, in which the internal bolster contains a pocket capable of receiving an extension rod. The method of inserting this embodiment includes essentially the same steps as those in the method described above. In this alternate method, however, the apparatus is assembled such that the pocket is left exposed. The rod is inserted into the pocket and used to push the assembly through the penetration. The rod is then removed from the penetration along with the sleeve and rip-cord.